Enhancing the Reversibility of Mg/S Battery Chemistry through Li+ Mediation

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• 作者：Tao Gao ; Malachi Noked ; Alex J Pearse ; Eleanor Gillette ; Xiulin Fan ; Yujie Zhu ; Chao Luo ; Liumin Suo ; Marshall A Schroeder ; Kang Xu ; Sang Bok Lee ; Gary W. Rubloff ; Chunsheng Wang
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：September 30, 2015
• 年：2015
• 卷：137
• 期：38
• 页码：12388-12393
• 全文大小：393K
• ISSN：1520-5126

文摘

Mg metal is a promising anode material for next generation rechargeable battery due to its dendrite-free deposition and high capacity. However, the best cathode for rechargeable Mg battery was based on high molecular weight Mg_xMo₃S₄, thus rendering full cell energetically uncompetitive. To increase energy density, high capacity cathode material like sulfur is proposed. However, to date, only limited work has been reported on Mg/S system, all plagued by poor reversibility attributed to the formation of electrochemically inactive MgS_x species. Here, we report a new strategy, based on the effect of Li⁺ in activating MgS_x species, to conjugate a dendrite-free Mg anode with a reversible polysulfide cathode and present a truly reversible Mg/S battery with capacity up to 1000 mAh/g_s for more than 30 cycles. Mechanistic insights supported by spectroscopic and microscopic characterization strongly suggest that the reversibility arises from chemical reactivation of MgS_x by Li⁺.